NorthAuraCollection

Bedside Reference

Nursing Lab Values Cheat Sheet

A high-yield reference to the lab values you'll see every shift — BMP, CBC, ABGs and coagulation panels — with the clinical significance nurses actually use at the bedside and on the NCLEX.

Basic Metabolic Panel (BMP)

Lab	Normal Range	Clinical Significance
Sodium (Na+)	135–145 mEq/L	Hyponatremia → seizures, confusion; hypernatremia → dehydration.
Potassium (K+)	3.5–5.0 mEq/L	High K+ → peaked T waves, arrhythmias; low K+ → U waves, weakness.
Chloride (Cl-)	98–106 mEq/L	Shifts with acid–base and fluid status.
Bicarbonate (HCO3-)	22–26 mEq/L	Metabolic acidosis vs. alkalosis marker.
BUN	7–20 mg/dL	Elevated in dehydration, GI bleed, renal injury.
Creatinine	0.6–1.2 mg/dL	Best single marker of renal function.
Glucose (fasting)	70–110 mg/dL	Hypoglycemia <70 → treat immediately.
Calcium	8.6–10.2 mg/dL	Low → Trousseau/Chvostek; high → bone pain, stones.
Magnesium	1.6–2.6 mg/dL	Low Mg often coexists with low K+.

Complete Blood Count (CBC)

Lab	Normal Range	Clinical Significance
WBC	4.5–11.0 × 10^9/L	Elevated → infection; low → immunocompromise.
RBC	4.2–5.9 × 10^12/L	Assess with H&H for anemia workup.
Hemoglobin	12–17 g/dL	Transfusion threshold often ~7 g/dL.
Hematocrit	36–52 %	Roughly 3× hemoglobin.
Platelets	150–400 × 10^9/L	<50 → bleeding risk; <20 → spontaneous bleeding.

Arterial Blood Gases (ABGs)

Lab	Normal Range	Clinical Significance
pH	7.35–7.45	<7.35 acidosis, >7.45 alkalosis.
PaCO2	35–45 mmHg	Respiratory component.
HCO3-	22–26 mEq/L	Metabolic component.
PaO2	80–100 mmHg	Oxygenation.
SaO2	95–100 %	Goal ≥92 % in most patients.

Coagulation & Cardiac

Lab	Normal Range	Clinical Significance
PT	11–13.5 sec	Extrinsic pathway; warfarin monitoring.
INR	0.8–1.1 (2–3 on warfarin)	Bleed risk rises >4.
aPTT	25–35 sec	Heparin monitoring — goal often 1.5–2.5×.
Troponin I	<0.04 ng/mL	Elevated → myocardial injury.
BNP	<100 pg/mL	Elevated in heart failure exacerbation.